Information about orthostatic hypotension (OH) among elderly patients hospitalized for acute conditions in short-term facilities is scarce. Many older inpatients carry various predisposing factors for OH. However, its existence goes frequently unrecognized. In this context, first morning standing up following admission for an acute disease may be dangerous. The aim of this study was to investigate OH and associated manifestations in this situation. OH (≥20 mmHg systolic and/or ≥10 mmHg diastolic blood pressure fall), heart rate, arrhythmias and appearance of dizziness or palpitations were recorded in 121 sequential inpatients aged >65 years, prior to and 1, 3 and 5 min following first morning standing. OH occurred in 64.5% of patients, while dizziness and/or palpitations appeared in 76%. Severe adverse effects were registered in 11.5% of OH patients. Significantly associated with OH were: bed rest lasting 9-24 h (vs ≤8 h, p<0.001), appearance of dizziness or palpitations (p<0.001 and p = 0.005, respectively), heart failure (p = 0.02) and renal dysfunction (p = 0.04). OH and/or associated symptoms are frequent in acutely ill older inpatients on first morning standing up following nocturnal bed rest. The ominous potential consequences call for alertness to this phenomenon and application of appropriate preventive measures.